Lotus seven

For the first time, the Lotus Seven was introduced to the public in 1957 as the cheapest sports car for use in British club races. Sales of assembly kits began in 1958 . The car was priced at $ 1,250 for a complete set (including engine).

The cars of the first series had a spatial frame, continuous rear axle, independent front suspension on A-shaped levers, drum brakes on all wheels, a 40-horsepower Ford engine and a 3-speed gearbox. The car weighed only 430 kg. After they began to install a 75-horsepower engine (and a 4-speed gearbox), the car began to accelerate to a speed of 100 km / h in 9 seconds.

In 1960, Series 2 was born. The frame has been simplified and the suspension modified. In 1966, Lotus moved to another plant and Lotus Seven decided to roll out production, but Graham Nearn of Caterham Cars placed a large order and production continued. In 1967, Caterham Cars became the exclusive distributor of Lotus Seven.

In 1968, Series 3 appeared on which, from 1969, a Lotus engine with two camshafts (1.6 liters and 115 hp) was installed. From 1969 to 1972, the unsuccessful Series 4 was produced, the design of which pushed fans away and in 1973 the rights to production were sold to Caterhem Cars, which began producing not the 4th, but the 3rd, “classic” series.

Due to the relatively simple design of the car, over 160 companies offered their replicas of Lotus Seven . These cars are also often called "sevenesque" , "seven" , "se7en" or "clubmans" . The following is a partial list of replicas:

• Birkin S3 , Lotus Seven replica
• Caterham 7
• Donkervoort Automobielen BV
• McGregor Motorsport Ltd (New Zealand) Lotus Seven replica kits and manufacturers
• Stalker V6 Clubman by Brunton Automotive USA

Series 1:

• 7F (Ford engine, 1172 cm³, 28-40 hp), 1957-1960
• 7C ( Coventry Climax engine, 1098 cm³, 75 hp) 1958-1960
• 7A (BMC engine, 948 cm³, 37 HP), 1958-1960
• 7 America (Austin-Healey engine, 43 hp), 1958-1960

Series 2:

• 7F (Ford engine, 1172 cm³, 40 hp), 1960-1961
• 7A (BMC engine, 948 cm³, 37 hp), 1960-1961
• 7 America (Austin-Healey engine, 1098 cm³, 55 hp), 1960-1961
• 7 105E (Ford engine, 997 cm³, 39 hp), 1961-1968
• Super 7 Cosworth 1340 ( Ford Cosworth engine, 1340 cm³, 85 h.p.), 1961-1962
• Super 7 1500 (Ford Cosworth engine, 1498 cm³, 66-100 h.p.), 1962-1968
• 7 Serie 2 1/2 (Ford engine, 1598 cm³, 84 hp), 1968

Series 3:

• 7 1300/1600 (Ford engine, 1297/1598 cm³, 72/84 hp), 1968-1969
• 7 S (Ford Holbay engine, 1598 cm³, 120 hp), 1969
• 7 SS (Lotus engine, 1558 cm³, 115-125 hp), 1969

Series 4:

• 7 1300 / 1600GT (Ford engine, 1297/1598 cm³, 72/84 HP), 1970-1972
• 7 Twin Cam (Lotus engine, 1558 cm³, 115-125 hp), 1970-1972

Engine

The first Seven series was made with a Ford 100E engine and a 3-speed gearbox. The later models were equipped with engines of Coventry Climax, known in those years for Formula 1 racing . The volume of engines from Austin A-35 was 1097 cm³ or 948 cc, the gearbox became a 4-speed, produced by British Motor Corp. (BMC). In 1960, the production of cars of the second series began. They had a lighter frame, new front wings and a fiberglass nose cone. At first, the engines remained the same, as in the first series. But soon they were replaced by more advanced Ford 105E engines with a volume of 997 cm³ and BMC (from Austin Healey Sprite). Since 1961, engines from Ford Classic 109E with a volume of 1340 cubic meters have been used. cm, and then since 1962 - from a Ford Cortina with a volume of 1498 cubic meters. cm.

Frame and body

The basis of the body was a spatial tubular frame of high torsional rigidity with a working lining of polished aluminum sheets. The frame trim and hood were replaced by exterior body panels, the fenders and the front fascia were made of sheet aluminum. The windshield and a lightweight tent that folded behind the back of the driver and passenger seats, as well as removable “soft” doors, protected the riders from the weather. The front wings were of a bicycle type, that is, they moved along with the steered wheels.

Weight

Initially, the weight of Lotus Seven did not exceed 500 kg.

Pendant

The front suspension was independent, on wishbones, using a stabilizer bar as a longitudinal element of the upper arm and a telescopic hydraulic shock absorber coaxial with the spring, resting on the lower arm. The rear suspension was made dependent, the rear beam from Ford cars was used in it.

Problems

The first Lotus Seven series had problems with the rear axle and differential. Later, with the release of the third series, these problems were resolved. The low corrosion resistance of the space frame also caused problems. .

• Jeremy Coulter. The Lotus and Caterham Sevens . Croydon: Motor Racing Publications Ltd., 1986. ISBN 0-947981-06-3
• Peter Ross "Lotus - The Early Years 1951-54." Coterie Press, 2004. ISBN 1-902351-12-6

• Caterham official website